Car seat base



FIG. 1 is a perspective view of the invention;

FIG. 2 is a top plan view of the invention;

FIG. 3 is a rear edge view of the invention;

FIG. 4 is a left side view of the invention;

FIG. 5 is a front edge view of the invention; and,

FIG. 6 is a bottom plan view of the invention. 

The ornamental design for a car seat base, as shown and described. 